Flotation of barite



'must have a specific gravity of 4.25 or higher. gravity of 4.20 is about an absolute minimum, anything United States Patent FLOTATION 0F BARITE Kenneth C. Vincent, Palo Alto, Calif., assignor to National Lead Company, New York, N. Y., a corporation of New York No Drawing. Application April 4, 1956 Serial No. 575,926

4 Claims. (Cl. 209-166) The present invention relates to the flotation of barite, and more particularly to the use of an improved petroleum sulfonate flotation agent.

In recent years the flotation of non-metallic minerals has become of increasing economic importance, and in particular it has become common to float barite, native barium sulfate, from gangue minerals, usually with the aid of an anionic collector such as a fatty acid or other long-chain organic radical coupled to an acid-forming group.

Much of the barite floated in this manner, from gangue minerals which may be limestone or various silicious minerals such as quartz, clay minerals, feldspar, and the like, often present in the form of clays or shales or limey shales and the like, is used as a weighting material for drilling mud. This end use imposes certain requirements upon the flotation process, one of which is ease in removing the flotation reagent from the beneficiated mineral, in view of the fact that a mineral containing a hydrophobic coating is not well-suited for use in an aqueous drilling fluid, where a hydrophilic surface is necessary not only for defiocculation and proper dispersal of the weighting material products, but also in order to avoid foaming when the weighting material is ;added to a typical drilling mud.

Moreover, barite as used for weighting drilling muds A specific less than this not being a commercial product in view of present-day standards in the consuming industry. It is necessary, therefore, that a concentrate rich enough in barium sulfate to give the stated minimum specific gravity be obtained. Anything less than this means that the flotation is unsuccessful from a commercial standpoint. This is a somewhat different situation from many applications of flotation of minerals, where any upgrading is of some help, provided that the metallurgical recovery is good. In floating barite for oil-well drilling use, metallurgical recovery is a secondary consideration, the primary consideration being specific gravity, i. e., barite assay, of the product, with the proviso, of course, that the metallurgical losses may not be too great.

Petroleum sulfonates of the oil-soluble type, commonly known as mahogany soaps, have been proposed for use as flotation reagents, and in a number of cases involving the flotation of non-metallic minerals, they have been used with success. Petroleum sulfonates of various kinds have been suggested as flotation agents for non-metallic minerals, for example in Nutter Patent No. 1,170,665, Harris Patent No. 2,120,217, Haygood Patent No. 2,069,182, Greene et al. Patent No. 2,303,931, and Keck Patent No. 2,373,688. The use of petroleum sulfonates in the field of barite flotation is limited, and froma commercial standpoint may be stated to be virtually nonexistent. Repeated attempts to adapt petroleum sulfonates to barite flotation have in general met with indifferent success, generally from the standpoint of poor overall beneficiation results, but also because of the lack ice of any improvement in the ease with which the flotation agent is removed. The standard flotation agent for barite in this country, accordingly, remains fatty acid soaps, as derived from animal fats, vegetable oils, or tall oil. Fatty acid flotation leaves much to be desired, however, since very careful control is required for successful and economical beneficiation, and the floated barite must be very carefully roasted at an elevated temperature, which must be maintained high enough to drive ofl the fatty acid residue, but not high enough to reduce any of the barite to barium sulfide, commonly known as black ash, for this is a flocculating contaminant in drilling muds.

An object of the present invention is to provide an improved flotation agent for barite flotation.

Another object of the present invention is to provide an improved petroleum sulfonate flotation agent, for use in barite flotation.

Another object of the present invention is to provide a means of producing a high specific gravity barite by flotation.

Other objects of the invention will become apparent as the description thereof proceeds.

In accordance with the invention, a mahogany sulfonate is used which is produced by sulfonating a California stock petroleum fraction containing from 30% to 36% aromatics, having a molecular weight of between 360 and 380, and a Saybolt universal viscosity of from 50 seconds to 55 seconds at 210 F., all of these figures applying to the oil prior to sulfonation. By California stock is meant the ordinary oil field usage of the name, namely crude oil from California sources. The sulfonation of this stock is carried out in accordance with the usual procedures, which are set forth in a number of sources, such as for example Ellis, Chemistry of Petroleum Derivatives, volumes 1 and 2, chapter 46 of each. A discussion of petroleum sulfonates generally is given in an article by Sperling in Industrial and Engineering Chemistry, volume 40, pages 890-897 (1948). In essence, the sulfonation treatment consists of three or four successive treatments with fuming sulfuric acid, most satisfactorily at from F. to F. The acid sludge is allowed to settle out. The oil layer remaining contains the product useful in accordance with this invention, and it is recovered therefrom by extraction with dilute ethanol and neutralization with caustic soda. The caustic soda may be dissolved in the dilute aqueous alcohol. The mahogany soap is then freed of water and alcohol by evaporation. The product recovered in this manner contains from three-fifths to two-thirds sulfonic acid in the form of an alkali metal salt, a very few percent of water, and, except for the sodium present to neutralize the sulfonic acids, the remainder consists of unreacted hydrocarbon oil.

In commercial practice, a product of this type may be obtained from a California stock lubricating oil fraction initially of 35 viscosity index, and 60 seconds Saybolt viscosity at 210 R, which is given a pretreatment with sulfuric acid in order to remove polycyclic compounds. This raw material, which typically will run 35% to 36% aromatics, is thus by the preliminary treatment described formed into the sulfonation stock for further treatment in accordance with the invention, and typically will have an aromatics content of 33%, a viscosity index of 35, a molecular weight of 370, and a Saybolt viscosity of 55 to 57 at 210 F., prior to the actual sulfa-nation treatment.

To recapitulate and summarize, the petroleum sulfonate concerned in this invention, and hereinafter occasionally termed inventive petroleum sulfonate, is an oil-soluble alkali metal petroleum sulfonate having a molecular weight of from 460 to 470, derived by the sulfonation and subsequent neutralization of a California stock petroleum fraction having a molecular weight of between 360 and 380 and containing from 30% to 36% aromatics. It will be understood that the petroleum sulfonate thus characterized will in general contain a varying amount of unreacted mineral oil, which it is difficult and uneconomical to separate from the sulfonate proper. It will be further understood that neutralization of the sul: fonated oil in order to recover the petroleum sulfonate therefrom may be carried out with any convenient alkali such as caustic soda, caustic potash, caustic lithia, ar'n.-. monia and the like, so that although I prefer a sodium sulfonate for inventive purposes, the petroleum sulfonate may also be a potassium, lithium, ammonium, or any similar alkali metal sulfonate.

The product obtained in the manner described is a collector for barite. and may be used by itself in barite flotation or in combination with other flotation and auxiliary flotation chemicals known to the art. One of the advantages of my sulfonate used in accordance with the invention is that in some cases it may be used indeed by itself, and in other cases, the only auxiliary reagent needed is a gangue depressant, such as sodium silicate.

In order to show the advantages peculiar to my sulfonate, I give below the results of comparative tests on a barite-calcite mixture using the sulfonate in accordance with the invention and also three commercially produced sulfonates offered for use as non-metallic mineral flotation agents, and considered to represent the best available sulfonates for. barite flotation prior to my invention.

The sulfonate which I have used was made in the. manner described hereinabove, and had the following characteristics: equivalent weight 460-470, specific gravity 1.05, water content 4.0%, inorganic salts 0.6%, viscosity, SSF at 210 F., 350.

The sulfonate indicated as Oronite in the test which follows was obtained from the Oronite Chemical Company, and is known as Oronite Purified Sulfonate-L. The sulfonate marked Petronate was a sulfonate sold by L. 'Son'nebornSon's, Inc. of New York under'the name of Petronate L. The sulfonate marked Mahogany Oil No.60 is a petroleum sulfonate sold under that name by Mineral Oil Refining'Company of Dickinson, Texas.

A high grade barite ore assaying over 99% barium sulfate was used,ground'to*95.8% minus 325 mesh. The calcite used was prepared from high grade calcite spar from a deposit in Hot Springs County, Arkansas, assaying 96.2% calcium carbonate and ground to 95.5% minus 325 mesh. In order to prepare an ore for'the test, these were mixed in the proportionef 50% barite and 50% calcite. In the flotation tests, "in all cases, 1.5 pounds per ton of the sulfonatewas used, as calculated on the feed, and 5.0 pounds per ton of sodium silicate as a gangue depressant. The 'pH'in the rougher was 9.0 in all 'cases, which dropped'to8.6 in the 'No. '1 cleaner, 8.5 in the No. 2 cleaner, a'nd 8.0 in the No. 3'clea11er. The results obtained were as follows:

TEST I.- PETROLEUM SULFONATEIN ACCORD- ANCE WI-T H THE INVENTION Assay, Percent Metallurgical Percent Sp. Recovery Weight Gr.

B21804 021003 1321804 CaGOa Head 3.37 48.82 48. 98 100.00 100.00

Flotation time Minutes Roughing 5 First cleaning '4 Second cleaning 3.5 Third cleaning 3 4 4 Fast floating and produces a very satisfactory froth which breaks down easily.

TEST II.ORONITE PURIFIED SULFONATE Assay, percent Metallurgical Recovery Percent Sp. Weight Gr.

B3504 C3003 13830.] C800:

Concentrate 48. 93 4. 03 82. 0 18. 0, 80. 50 1G. 41 Middling 3 5. 29 3. 27 43. 3 56. 7 4. 60 5. 98 Middllng 2- 7. 02 3. 01 26. 3 73. 7 3. 72 10. 63 Mlddllng 1 12. 00 2.92 20. 6 79. 4 4. 96 19. 18 Ta1ltng 2G. 76 2. 79 11. 4 B8. 6 6.13 47. 80

Head 3. 38 49. 78 48. 64 100. 00 100. 00

Flotation time Minutes Roughing -2 6.5 First cleaning 5.0 Second cleaning 4.5 Third cleaning 4.0

Slower floating than the inventive sulfonate. Rougher concentrate not as clean, and a more voluminous froth which persists through all cleaning stages. Froth handling in a large scale operation would probably present a problem.

TEST III.PETRONATEL A ssay, percent Metallurgical Recovery Percent Sp. Weight Gr.

B11804 OaCO; ZBaSO; 011003 3. 99 so. a 19. 7 88. 64 19.06 3.00 25. 5 74. 5 2. 55 7. 57 .2. 89 18. 3 81. 7 2. 17 9. s9 2. 12. 2 87. 8 2. 53 18.72 2.76 8. 8 91. 2 4.21 44. 7G

Flotation time Minutes Roughing 5.0 First cleaning 4.5 Second cleaning 4.0 Third cleaning 3.5

The froth was similar to the inventive sulfonate, but somewhat more voluminous and not as clean.

TEST IV.-'MAHOGANY OIL NO. 60

required a. short flotation time.

Inspection of the above-tests shows that a concentrate having a-specific gravity. of 4.27 wasobtained with the 'inventive petroleum sulfonate, twith;a.metallurgical recovery of substantially 80%, with, less them-8% tbarite loss in. thetailing 011. thev othen hand,;;using.-the. Oronite sulfonate, a specific gravity of only 4.03 was obtained with substantially the same metallurgical recovery. Using Petronate-L, a concentrate of specific gravity of only 3.99 was obtained, which was far below the minimum, so that the relatively high metallurgical recovery was not an advantage. Using the Mahogany Oil No. 60, a concentrate having a specific gravity of 4.17 was obtained, which while still considerably better than that obtained with the other sulfonates tested, with of course the ex-. ception of the inventive sulfonate, was still below the minimum commercial value of 4.20 to 4.25, and in addition would be ruled out from an economic standpoint because of the low metallurgical recovery of about 67%.

It will be understood that my inventive sulfonateprocess may be used with other flotation agents and metallurgical recovery aids additionally present. For example, it is in many cases desirable to use a gangue depressant tailored to the particular gangne problem involved. Frothers may be used, such as alcohols with medium molecular weight, and various other additives may be used to improve the character of the froth; fuel oil or other hydrocarbon oils over and above the mineral oil normally present in the petroleum sulfonate may be added; and finally, the inventive process may be used in combination with other collectors such as fatty acids, vegetable Oilsg or from tall oil. A discussion of flotation practice generally may be found in the book Flotation by Gaudin, New York 1932, and the book Principles of Flotation by Wark, Melbourne 1938, as well as the book Schwimmaufbereitung by Petersen, Dresden and Leipzig 1936. Reference may be made to these works for further details of practice common in the flotation art.

The barite products obtained in accordance with the invention may be readily freed of flotation agent residue by heating, as for example in a direct or indirect fired rotary kiln, or other suitable roasting apparatus.

In the claims which follow, the petroleum sulfonate has been designated as a mahogany petroleum sulfonate, which it will be appreciated is in accordance with the disclosure herein. This terminology serves to distinguish from other petroleum sulfonates, which may be present in the acid sludge layer, which sulfonates or green acids form no part of the present invention.

The molecular weight of the sulfonate used in accordance with the invention has been specified quantitatively. It will be understood that this is as determined on the sulfonate portion proper, naturally not including any mineral oil which may be present. Furthermore, it is to be understood that the term molecular weight is taken as synonymous with equivalent weight, as this is the practice in this field, and corresponds with the fact that so far as is known, the molecules of the mahogany petroleum sulfonates at hand contain only one sulfonic group.

It will further be understood that while a sulfonation stock from a California crude oil has been specified, it is not to be intended to limit the practice of the invention to sulfonation stocks actually arising from California crude, but a definite type of crude has been established thereby, and crude petroleum oil from other areas having essentially the same characteristics as far as asphaltic content and naphthenic content will serve as effective substitutes for a crude actually arising from California oil fields, and such oil is therefore to be understood as coming within the scope of the claims.

It will be understood that the invention is a broad one, and numerous changes may be made in details thereof, within the scope of this specification and the claims which follow,

What I claim is:

1. In the concentration of barite from a comminuted barite-containing ore by a process of flotation, the steps comprising: treating the comminuted ore with a mahogany petroleum sulfonate derived by the sulfonation with fuming sulfuric acid of a California stock hydrocarbon petroleum fraction having a molecular weight of between 360 and 380 and containing from 30% to 36% aromatics, said petroleum sulfonate having a molecular weight of from 460 to 470, so as to render the barite particles floatable, and subjecting the so-treated ore to froth flotation.

2. In the concentration of barite from a comminuted barite-containing ore by a process of flotation, the steps comprising: treating the comminuted ore with a mahogany petroleum sulfonate derived by the sulfonation with fuming sulfuric acid of a California stock hydrocarbon petroleum fraction having a molecular weight of between 360 and 380 and containing from 30% to 36% aromatics, said petroleum sulfonate having a molecular weight of from 460 to 470, so as to render the barite particles floatable, subjecting the so-treated ore to froth flotation, and roasting the recovered barite so as to produce a concentrated barite product substantially free of petroleum sulfonate residue.

3. In the concentration of barite from a comminuted barite-containing ore by a process of flotation, the steps comprising: treating the comminuted ore with a mahogany petroleum sulfonate derived by the sulfonation with fuming sulfuric acid of a California Stock hydrocarbon petroleum fraction having a molecular weight of between 360 and 380 and containing from 30% to 36% aromatics, said petroleum sulfonate having a molecular weight of from 460 to 470, so as to render the barite particles floatable, and subjecting the so-treated ore to froth flotation so as to recover a barite of specific gravity at least 4.20.

4. In the concentration of barite from a comminuted barite-containing ore by a process of flotation, the steps comprising: treating the comminuted ore with a mahogany petroleum sulfonate derived by the sulfonation with fuming sulfuric acid of a California Stock hydrocarbon petroleum fraction having a molecular weight of between 360 and 380 and containing from 30% to 36% aromatics, said petroleum sulfonate having a molecular weight of from 460 to 470, so as to render the barite particles floatable, subjecting the so-treated ore to froth flotation so as to recover a barite of specific gravity at least 4.20, and roasting the recovered barite so as to produce a concentrated barite product substantially free of petroleum sulfonate residue.

OTHER REFERENCES Rock Products, May 1947, page 94, column 3. 

1. IN THE CONCENTRATION OF BARITE FROM A COMMINUTED BARITE-CONTAINING ORE BY A PROCESS OF FLOTATION, THE STEPS COMPRISING: TREATING THE COMMINUTED ORE WITH A MAHOGANY PETROLEUM SULFONATE DERIVED BY THE SULFONATION WITH FUMING SULFURIC ACID OF A CALIFORNIA STOCK HYDROCARBON PETROLEUM FRACTION HAVING A MOLECULAR WEIGHT OF BETWEEN 360 AND 380 AND CONTAINING FROM 30% TO 36% AROMATICS, SAID PETROLEUM SULFONATE HAVING A MOLECULAR WEIGHT OF FROM 460 TO 470, SO AS TO RENDER THE BARITE PARTICLES FLOATABLE, AND SUBJECTING THE SO-TREATED ORE TO FROTH FLOTATION. 